Storage system and method for performing and authenticating write-protection thereof

ABSTRACT

In one embodiment, the method includes receiving, at a storage device, a request. The request includes a request message authentication code and write protect information. The write protect information includes at least one of start address information and length information. The start address information indicates a logical block address at which a memory area in a non-volatile memory of the storage device starts, and the length information indicates a length of the memory area. The method also includes generating, at the storage device, a message authentication code based on (1) at least one of the start address information and the length information, and (2) a key stored at the storage device; authenticating, at the storage device, the request based on the generated message authentication code and the request message authentication code; and processing, at the storage device, the request based on a result of the authenticating.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/443,289, filed on Jun. 17, 2019, which is a continuation of U.S.application Ser. No. 15/962,581, filed on Apr. 25, 2018, and issued asU.S. Pat. No. 10,324,864, which is continuation of U.S. application Ser.No. 14/631,349, filed on Feb. 25, 2015, and issued as U.S. Pat. No.9,984,007 on May 29, 2018, which claims priority under 35 U.S.C. § 119to U.S. Provisional Patent Application No. 61/971,673, filed on Mar. 28,2014 and Korean Patent Application No. 10-2014-0117786, filed on Sep. 4,2014, in the Korean Intellectual Property Office, the entire contents ofeach of the above-referenced applications are hereby incorporated byreference.

BACKGROUND

The inventive concepts described herein relate to a storage system, andmore particularly, relate to a storage system and a write-protectionmethod thereof.

A storage system includes a host and a storage device. The host and thestorage device are connected through a variety of standardizedinterfaces, such as a serial ATA (SATA), universal flash storage (UFS),a small computer small interface (SCSI), a serial attached SCSI (SAS),and an embedded MMC (eMMC).

In a conventional storage device, anyone sets and releases writeprotection by means of a predetermined command. A type of the writeprotection is also set by a command. In addition, even though the writeprotection is set, anyone can release the write protection or change thesetting of the write protection.

Write-protected, for example, is a boot loader or a kernel image of anoperating system. Since anyone releases the write protection or changesits setting, the boot loader or the kernel image is exposed todangerous, unallowed access, such as rooting.

SUMMARY

At least one embodiment is directed to a non-transitory computerreadable medium.

In one embodiment, the non-transitory computer readable medium stores adata structure that controls a write protection operation of a storagedevice during execution of the write protection operation for anon-volatile memory in the storage device, the data structure includinga memory partition identifier identifying a partition of thenon-volatile memory, start address information indicating a logicalblock address for a memory area in the identified memory partition, andlength information indicating a length of the memory area in theidentified memory partition; and the data structure including typeinformation instructing the storage device on a type of write protectionto provide the memory area for the write protection operation.

In one embodiment, if the length information is a reference value, thelength information indicates to apply write protection to an entirety ofthe identified memory partition.

In one embodiment, the data structure further includes writableinformation indicating whether to apply write protection to the memoryarea.

In one embodiment, the type information indicates a type selected from agroup including at least a first type, the first type indicates that thewritable information may be changed once after each power on of thememory, and that the writable information indicates to apply writeprotection at the powering on of the memory.

In one embodiment, the group includes the first type, a second type anda third type; the second type indicates that the writable informationmay be changed, and that the writable information indicates noapplication of write protection after the powering on of the memory; andthe third type indicates that the writable information may be changed.

At least one embodiment relates to a storage device.

In one embodiment, the storage device includes a first memory. The firstmemory is a non-volatile memory. The memory device also includes asecond memory configured to store a memory partition identifieridentifying a partition of the first memory, start address informationindicating a logical block address for a memory area in the identifiedmemory partition, and length information indicating a length of thememory area in the identified memory partition. The second memory isconfigured to store writable information in association with the startaddress information and the length information. The writable informationindicates whether to apply write protection to the memory area.

In one embodiment, the second memory is configured to store typeinformation in association with the start address information and thelength information, where the type information indicates a type of writeprotection to provide the memory area.

At least one embodiment relates to a method.

In one embodiment, the method includes receiving, at a storage device, arequest. The request includes a request message authentication code andwrite protect information. The write protect information includes atleast one of start address information and length information. The startaddress information indicates a logical block address at which a memoryarea in a non-volatile memory of the storage device starts, and thelength information indicates a length of the memory area. The methodalso includes generating, at the storage device, a messageauthentication code based on (1) at least one of the start addressinformation and the length information, and (2) a key stored at thestorage device; authenticating, at the storage device, the request basedon the generated message authentication code and the request messageauthentication code; and processing, at the storage device, the requestbased on a result of the authenticating.

In one embodiment, the write protection information includes both thestart address information and the length information; and the generatinggenerates the generated message authentication code based on the startaddress information, the length information and the key.

In one embodiment, the write protection information includes the startaddress information, the length information and a partition identifier.The partition identifier identifies a partition in the non-volatilememory of the storage device, and the partition includes the memoryarea. Also, the generating generates the generated messageauthentication code based on the start address information, the lengthinformation, the partition identifier and the key.

In one embodiment, the write protection information includes the startaddress information, the length information, the partition identifier,and writable information indicating whether to apply write protection tothe memory area; and the generating generates the generated messageauthentication code based on the start address information, the lengthinformation, the partition identifier, the writable information and thekey.

In one embodiment, the write protection information includes the startaddress information, the length information, the partition identifier,the writable information, and type information indicating a type ofwrite protection to provide the memory area; and the generatinggenerates the generated message authentication code based on the startaddress information, the length information, the partition identifier,the writable information, the type information and the key.

In one embodiment, the type information indicates a type selected from agroup including at least a first type, where the first type indicatesthat the writable information may be changed once after power on of thememory, and that the writable information indicates to apply writeprotection at the powering on of the memory.

In one embodiment, the group includes the first type, a second type anda third type. The second type indicates that the writable informationmay be changed, and that the writable information indicates noapplication of write protection after the powering on of the memory. Thethird type indicates that the writable information may be changed.

In one embodiment, the generating generates a hash-based messageauthentication code.

In one embodiment, the authenticating authenticates the request if thegenerated message authentication code matches the request messageauthentication code; and the processing processes the request if therequest is authenticated.

In one embodiment, the request requests the storage device to update thewrite protection information with information included in the request.

In one embodiment, the processing includes incrementing an updatecounter if the processing processes the request; and sending a responsemessage if the processing processes the request. The response messageincludes a count value of the update counter.

In one embodiment, the processing includes sending a response message inresponse to the request if the processing processes the request.

In one embodiment, the processing includes storing the write protectioninformation.

In a further embodiment, the method includes receiving, at a storagedevice, a write command to write data to a first area of a non-volatilememory in the storage device; and determining, at the storage device,whether to process the write command based on stored write protectioninformation for one or more memory areas covered by the first area, foreach memory area. The write protection information includes startaddress information indicating a logical block address of a start of thememory area, length information indicating a length of the memory area,and writable information indicating whether to apply write protection tothe memory area.

In one embodiment, the determining determines not to process the writecommand if the first area overlaps one of the memory areas havingassociated writable information indicating to apply write protection.

In one embodiment, the determining determines the first area overlapsone of the memory areas if an address associated with the write commandfalls within one of the memory areas.

In one embodiment, for each memory area, the write protectioninformation further includes a partition identifier, the partitionidentifier identifying a partition in the non-volatile memory, thepartition including the memory area. If the length information is set toa reference value, the length information indicates an entirety of theidentified partition is write protected. The determining determines notto process the write command if the first area overlaps one of thememory areas having associated length information set to the referencevalue.

In another embodiment, the method includes storing write protectioninformation for a memory area of a non-volatile memory. The writeprotection information includes writable information and typeinformation. The writable information indicates whether to apply writeprotection to the memory area, and the type information indicates a typeselected from a group including at least a first type. The methodfurther includes permitting changing the writable information once aftereach power on of the memory if the type information is the first type;and setting the writable information to indicate to apply writeprotection after power on of the memory if the type information is thefirst type.

In yet another embodiment, the method includes sending a request to astorage device, where the request requests that the storage deviceupdate write protection information for a memory area of a non-volatilememory in the storage device. The request includes write protectioninformation. The write protection information includes start addressinformation indicating a logical block address of a start of the memoryarea, length information indicating a length of the memory area, andwritable information indicating whether to apply write protection to thememory area.

Yet another embodiment relates to a storage device.

In one embodiment, the storage device includes a non-volatile memory anda controller. The controller is configured to receive a request. Therequest includes a request message authentication code and write protectinformation. The write protect information includes at least one ofstart address information and length information. The start addressinformation indicates a logical block address at which a memory area ofthe non-volatile memory starts, and the length information indicating alength of the memory area. The controller is configured to generate amessage authentication code based on (1) at least one of the startaddress information and the length information, and (2) a key stored atthe storage device. The controller is configured to authenticate therequest based on the generated message authentication code and therequest message authentication code; and the controller is configured toprocess the request based on a result of the authenticating.

In another embodiment, the storage device includes a non-volatile memoryand a controller. The controller is configured to receive a writecommand to write data to a first area of a non-volatile memory in thestorage device, and to determine whether to process the write commandbased on stored write protection information for one or more memoryareas covered by the first area. For each memory area, the writeprotection information includes start address information indicating alogical block address of a start of the memory area, length informationindicating a length of the memory area, and writable informationindicating whether to apply write protection to the memory area.

BRIEF DESCRIPTION OF THE FIGURES

The above and other objects and features will become apparent from thefollowing description with reference to the following figures, whereinlike reference numerals refer to like parts throughout the variousfigures unless otherwise specified, and wherein

FIG. 1 is a block diagram schematically illustrating a storage system;

FIG. 2 is a block diagram schematically illustrating a flashmemory-based UFS system;

FIG. 3 is a block diagram schematically illustrating a storage systemaccording to an embodiment of the inventive concepts;

FIG. 4 is a conceptual diagram showing an embodiment where awrite-protection area is appointed by the logical block address providedby a host;

FIG. 5 is a conceptual diagram showing an embodiment where a wholepartition of a storage device is write-protected;

FIG. 6 is a conceptual diagram showing an embodiment where awrite-protect (WP) descriptor is set to a ‘NV-P’ type;

FIG. 7 is a timing diagram showing a request and a response for lockingor unlocking write-protect of a storage system according to anembodiment of the inventive concepts;

FIG. 8 is a conceptual diagram for describing a method of calculating aHMAC;

FIG. 9 is a flow chart schematically illustrating a HMAC authenticationmethod of the storage system shown in FIG. 3;

FIG. 10 is a flow chart for describing a write-protection executionmethod of the storage system shown in FIG. 3;

FIG. 11 is a conceptual diagram schematically illustrating an embodimentin which one or more areas of a storage system according to anembodiment of the inventive concepts are write-protected;

FIG. 12 is a block diagram schematically illustrating a hardwareconfiguration of a storage device based on a flash memory shown in FIG.3;

FIG. 13 is a block diagram schematically illustrating a software layerstructure;

FIG. 14 is a block diagram illustrating a solid state drive to which astorage device according to the inventive concepts is applied;

FIG. 15 is a block diagram schematically illustrating the SSD controllershown in FIG. 14;

FIG. 16 is a block diagram schematically illustrating an electronicdevice including a storage device according to an embodiment of theinventive concepts; and

FIG. 17 is a block diagram schematically illustrating a memory card towhich a storage device of a user device according to an embodiment ofthe inventive concepts is applied.

DETAILED DESCRIPTION

Embodiments will be described in detail with reference to theaccompanying drawings. The inventive concepts, however, may be embodiedin various different forms, and should not be construed as being limitedonly to the illustrated embodiments. Rather, these embodiments areprovided as examples so that this disclosure will be thorough andcomplete, and will fully convey the concepts of the inventive conceptsto those skilled in the art. Accordingly, known processes, elements, andtechniques are not described with respect to some of the embodiments ofthe inventive concepts. Unless otherwise noted, like reference numeralsdenote like elements throughout the attached drawings and writtendescription, and thus descriptions will not be repeated. In thedrawings, the sizes and relative sizes of layers and regions may beexaggerated for clarity.

It will be understood that, although the terms “first”, “second”,“third”, etc., may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another region, layer or section. Thus, a firstelement, component, region, layer or section discussed below could betermed a second element, component, region, layer or section withoutdeparting from the teachings of the inventive concepts.

Spatially relative terms, such as “beneath”, “below”, “lower”, “under”,“above”, “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below” or “beneath”or “under” other elements or features would then be oriented “above” theother elements or features. Thus, the example terms “below” and “under”can encompass both an orientation of above and below. The device may beotherwise oriented (rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein interpreted accordingly. Inaddition, it will also be understood that when a layer is referred to asbeing “between” two layers, it can be the only layer between the twolayers, or one or more intervening layers may also be present.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the inventiveconcepts. As used herein, the singular forms “a”, “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Also, the term “example” is intended to referto an example or illustration.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to”, “coupled to”, or “adjacent to” anotherelement or layer, it can be directly on, connected, coupled, or adjacentto the other element or layer, or intervening elements or layers may bepresent. In contrast, when an element is referred to as being “directlyon,” “directly connected to”, “directly coupled to”, or “immediatelyadjacent to” another element or layer, there are no intervening elementsor layers present.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this inventive concepts belongs.It will be further understood that terms, such as those defined incommonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand/or the present specification and will not be interpreted in anidealized or overly formal sense unless expressly so defined herein.

FIG. 1 is a block diagram schematically illustrating a storage system.Referring to FIG. 1, a storage system 1000 contains a host 1100 and astorage device 1200. The host 1100 and the storage device 1200 may beconnected through a variety of standardized interfaces, such as a serialATA (SATA), universal flash storage (UFS), a small computer smallinterface (SCSI), a serial attached SCSI (SAS), and an embedded MMC(eMMC).

As illustrated in FIG. 1, a host interface 1101 and a device interface1201 are connected through data lines DIN and DOUT for exchanging dataor signals and a power line PWR for providing a power. The host 1100includes a processor 1105, a host controller 1130, and a buffer memory1140.

The processor 1105 executes an application program 1110 and a devicedriver 1120. The application program 1110 may be one of variousapplication programs to be executed by the host 1100. The device driver1120 may drive peripheral devices that are used through connection withthe host 1100, and may drive the storage device 1200, for example. Theapplication 1110 and the device driver 1120 may be separate softwaremodules that are stored and/or loaded into the buffer memory 1140. In analternative embodiment, hardware logic circuits configured by theapplication program 1110 and the device driver 1120 as firmware mayreplace the processor 1105. As a further alternative, a combination of aprocessor and hardware logic circuits may be used. In yet anotherembodiment, the processor 1105 and/or hardware logic circuits may beinternal to the host controller 1130 instead of external. The hostcontroller 1130 exchanges data with the storage device 1200 through thehost interface 1101. In one embodiment, the host controller 1130includes one or more central processing units (CPUs). In an alternativeembodiment, the host controller 1130 may include hardware logic circuitsconfigured by firmware. In yet another embodiment, the host controller1130 may be combination of CPU(s) and hardware logic circuits.

The buffer memory 1140 is used as a main memory and/or a cache memory ofthe host 1100, and is also used as a driving memory for drivingsoftware, such as the application 1110 or the device driver 1120.

The storage device 1200 is connected to the host 1100 through the deviceinterface 1201. The storage device 1200 includes a nonvolatile memory1210, a device controller 1230, and a buffer memory 1240. Thenonvolatile memory 1210 may include the following: flash memory, MRAM,PRAM, FeRAM, etc. The device controller 1230 controls an overalloperation of the nonvolatile memory 1210 including a write operation, aread operation, an erase operation, etc. The device controller 1230 mayinclude one or more programmed CPUs, configured hardware logic circuits,or a combination thereof. The device controller 1230 exchanges anaddress with the nonvolatile memory 1210 or the buffer memory 1240 ordata with the nonvolatile memory 1210 or the buffer memory 1240 througha data bus.

The buffer memory 1240 may be used to temporarily store data read fromthe nonvolatile memory 1210 or to be stored therein. The buffer memory1240 may be implemented with a volatile memory or a nonvolatile memory.The buffer memory 1240 may be embedded in the device controller 1230 ormay be integrated along with the device controller 1230.

The storage system 1000 shown in FIG. 1 is applicable to a mobile deviceor any other electronic device that is based on a flash memory. Below,universal flash storage (UFS) may be an example to describe aconfiguration and an operating method of the storage system 1000 shownin FIG. 1.

FIG. 2 is a block diagram schematically illustrating a flashmemory-based UFS system. Referring to FIG. 2, an UFS system 2000includes an UFS host 2100 and an UFS device 2200.

The UFS host 2100 includes a processor 2105, a host controller 2130, anda buffer RAM 2140. The processor 2105 executes application programs 2110and device drivers 2120. The application program 2110 may be one ofvarious application programs to be executed by the host 2100. The devicedrivers 2120 may drive peripheral devices that are used throughconnection with the host 2100, and may drive the UFS device 2200, forexample. The application 2110 and the device driver 2120 may be separatesoftware modules that are stored and/or loaded into the buffer RAM 2140.In an alternative embodiment, hardware logic circuits configured by theapplication program 2110 and the device driver 2120 as firmware mayreplace the processor 2105. As a further alternative, a combination of aprocessor and hardware logic circuits may be used. In yet anotherembodiment, the processor 2105 and/or hardware logic circuits may beinternal to the host controller 2130 instead of external. The hostcontroller 2130 exchanges data with the UFS device 2200 through the hostinterface 2101. The host controller 2130, same as host controller 1130,may include one or more CPUs, hardware logic circuits or a combinationthereof. As shown in FIG. 2, the host controller 2130 is configured toinclude a command queue 2131, a host DMA 2132, and a power manager 2133.Commands (e.g., a write command) generated by the controller 2130executing the UFS application 2110 and the device driver 2120 aremanaged by the command queue 2131 of the host controller 2130. Thecommand queue 2131 sequentially manages commands to be provided to theUFS device 2200. Provided to the host DMA 2132 are the commands that arestored in the command queue 2131. The host DMA 2132 sends the commandsto the UFS device 2200 through a host interface 2101.

The UFS device 2200 includes a flash memory 2210, a device controller2230, and a buffer RAM 2240. The device controller 2230 includes one ormore programmed CPUs, configured hardware logic circuits or acombination thereof. As configured, the host controller 2230 includes acommand manger 2232, a flash DMA 2233, a security manager 2234, a buffermanager 2235, a flash translation layer (FTL) 2236, and a flash manager2237.

A command transferred from the UFS host 2100 to the UFS device 2200 isprovided to the command manager 2232 through a device interface 2201.The command manager 2232 analyzes a command provided from the UFS host2100, and authenticates the command by means of the security manager2234. The command manager 2232 allocates the buffer RAM 2240 so as toreceive data through the buffer manager 2235. Being ready to transferdata, the command manager 2232 sends RTT (READY_TO_TRANSFER) UPIU to theUFS host 2100. A packet based on the UFS standard is referred to UPIU.

The UFS host 2100 sends data to the UFS device 2200 in response to theRTT UPIU. The data is sent to the UFS device 2200 through the host DMA2132 and the host interface 2101. The UFS device 2200 stores thereceived data in the buffer RAM 2240 through the buffer manager 2235.The data stored in the buffer RAM 2240 is provided to the flash manger2237 through the flash DMA 2233. The flash manager 2237 stores data at aselected address of the flash memory 2210, based on address mappinginformation of the FTL 2236.

If a data transfer operation and a program operation for a command arecompleted, the UFS device 2200 may send a response signal to the UFShost 2100 through an interface and may inform the UFS host 2100 ofcommand completion. The UFS host 2100 informs the device driver 2120 andthe application 2110 executing on the host controller 2130 of whether acommand corresponding to the response signal is processed, and thenterminates an operation on the command.

Providing reliability and security when the UFS system 2000 is used in amobile device involves setting and releasing write protection data. TheUFS system 2000 according to an embodiment of the inventive concepts mayauthenticate a command by means of Key-ed Crypto Hash, private key, andrequest count.

The inventive concepts may set or release the write protection throughan authentication procedure or may change an attribute or type of thewrite protection. Also, the inventive concepts may appoint awrite-protection area by a unit of a logical block address LBA of a host2100.

I. WP (Write-Protect) Descriptor's Structure

FIG. 3 is a block diagram illustrating another embodiment of theinventive concepts. In one embodiment, the host 3100 may be the same asthe host 2100. The storage device 3200 may be the same as the storagedevice 2200. In another embodiment, the storage device 3200 may have thehardware configuration shown in FIG. 12.

FIG. 12 is a block diagram schematically illustrating a hardwareconfiguration of a storage device based on a flash memory-based UFSsystem shown in FIG. 3. FIG. 13 is a block diagram schematicallyillustrating a software layer structure executed by the CPU 3210 in thememory controller 3200 b of the storage device 3200.

Referring to FIG. 12, the storage device 3200 contains a flash memory3200 a and a memory controller 3200 b. The memory controller 3200 b isconnected to the host 3100 through a host interface controller 3201 andto the flash memory 3200 a through a flash interface controller 3202.The memory controller 3200 b contains a central processing unit (CPU)3210, a code RAM 3221, a data RAM 3222, a buffer RAM 3223, a ROM 3230, adirect memory access (DMA) 3240 for directly accessing a memory,hash-based message authentication code (HMAC) 3250 for data security,AES (Advanced Encryption Standard) 3260, and ECC (error correctionscoding) 3270 for correcting data errors. The DMA 3240, the HMAC 3250,the AES 3260 and the ECC 3270 are hardware logic circuits.

The CPU 3210 controls an overall operation of the memory controller 3200b. For example, at booting, the CPU 3210 loads a boot code stored in theflash memory 3200 a or the ROM 3230 on the code RAM 3221 to control thebooting of the storage device 3200.

Referring to FIG. 13, a software layer structure of the storage device3200 includes a host interface layer (HIL) 110, a security layer (SEL)115, a flash translation layer (FTL) 120, a flash interface layer (FIL)130, and a flash recovery layer (FRL) 140.

Based on the host interface layer (HIL) 110, the CPU 3210 may controloperations of receiving data from a host through the host interfacecontroller 3201 and storing the received data at the data RAM 3221. TheHIL 110 may include the command manager 3232. When exchanging data withthe host, the CPU 3210 uses the security layer (SEL) 115 to authenticatea host command and set an area to be write-protected. The security layer(SEL) 115 may include the security manager 3234.

Based on the flash interface layer (FIL) 130, the CPU 3210 provides datastored at the data RAM 3222 or the buffer RAM 3223 to the flash memory3200 a through the flash interface controller 3202. The CPU 3210 managesaddress mapping of the flash memory 3200 a, depending on the flashtranslation layer (FTL) 120. The CPU 3210 manages a recovery operationof the flash memory 3200 a, depending on the flash recovery layer (FRL)140.

The WP descriptor is stored at a nonvolatile memory, such as a flashmemory 2210 or 3200 a, or a ROM (not shown), and is loaded onto avolatile memory, such as a DRAM or an SRAM (e.g., buffer RAM 2240 or3223), at power-on. The WP descriptor is used to set or release thewrite protection or to change an attribute of the write protection.

The following table 1 shows a structure and a description of the WPdescriptor.

TABLE 1 Name Description PID(Partition Partition ID for application ofwrite protection ID) Start LBA Start address for write protection LengthSize to be write-protected If length is ‘0’, the whole partition iswrite-protected. Writable Whether to apply write protection withTrue/False Type P Maintain write protection until power-off or hardware(HW) reset. Always change Writable into True after power-on. If False,remains False until HW reset or power-on. Type NV-P Always changeWritable to False after power-off or HW reset even though Writable ischanged and applied by request. Type NV Change Writable only by request.

Referring to the table 1, the WP descriptor consists of ‘partition ID’(PID), ‘start LBA’, ‘length’, ‘writable’, and ‘type’. The partition ID(PID) is used to identify a partition of the flash memory to bewrite-protected. The start LBA denotes a start address of a logicalblock to be write-protected. The length means the size of an area to bewrite-protected.

FIG. 4 is a conceptual diagram showing an embodiment where awrite-protection area is defined in part by the logical block address ofa host. Referring to FIG. 4, a partition ID is ‘1’. That is, a firstpartition is identified. A start LBA and a length of a WP Descriptor are‘100’ and ‘900’, respectively. Thus, the write-protection area startsfrom LBA 100 and ends at LBA 1000. Namely, the start LBA and lengthdefine the memory area of the partition, which may be write protected.

FIG. 5 is a conceptual diagram showing an embodiment where the wholepartition is write-protected. Referring to a table 1, when the length ofa WP descriptor is set to ‘0’, the whole partition is write-protected.In an embodiment shown in FIG. 5, a partition ID and a length of a WPdescriptor are ‘1’ and ‘0’, respectively. Thus, the whole partition 1 iswrite-protected.

Referring to the table 1, ‘Writable’ denotes whether write protection isapplied. ‘Writable’ may be set to ‘True’ or ‘False’. An area where‘Writable’ is set to ‘True’ is writable, and not write-protected. Anarea where ‘Writable’ is set to ‘False’ is write-protected.

Referring to the table 1, the write protection is divided into threetypes. A ‘P’ type is a type where the write protection is maintaineduntil power-off or hardware reset. After power-on, ‘Writable’ is alwayschanged to ‘True’. When set to ‘False’, ‘Writable’ is not changed untilpower-off or hardware reset. A ‘NV’ type is a type where ‘Writable’ isonly changed by a request of a host 2100 or 3100. A ‘NV-P’ type is atype where ‘Writable’ is changed by a request of the host 2100 or 3100.However, when a WP descriptor is set to the ‘NV-P’ type, ‘Writable’ isalways changed to ‘False’ after power-off or hardware reset.

FIG. 6 is a conceptual diagram showing an embodiment where a WPdescriptor is set to a ‘NV-P’ type. Referring to FIG. 6, ‘partition ID’(PID), ‘Start LBA’, ‘Length’, ‘Writable’, and ‘Type’ of a WP descriptorare set to ‘1’, ‘100’, ‘900’, ‘True’, and ‘NV-P’, respectively. Atpower-off or hardware reset of a storage system 2000 or 3000, ‘Writable’is changed to ‘False’ because the WP descriptor is set to the ‘NV-P’type. When write-protected, an area (from LBA 100 to LBA 1000) is notwritable.

The following table 2 shows an example of initial values of the WPdescriptor shown in FIG. 3 for discussion purposes. The WP descriptormay be set with values shown in the table 2 as a default state.

TABLE 2 PID (Partition ID) Start LBA Length Writable Type 1 0 0 True P 20 0 True P 3 0 0 True P . . . . . . . . . . . . . . . n 0 0 True P

Referring to the table 2, a storage area of a storage device 2200 or3200 is divided into n partitions. Start LBAs and sizes of thepartitions PID1 through PIDn are set to ‘0’. The whole partition iswrite-protected because a length is set to ‘0’. In each of thepartitions PID1 through PIDn, ‘Writable’ is set to ‘True’ and a type isset to T′.

The following table 3 shows an example, for discussion purposes, of aconfiguration of a WP descriptor at a point in time when a storagesystem 2000 or 3000 is operating.

TABLE 3 PID (Partition ID) Start LBA Length Writable Type 1 0 5000 FalseP 2 0 4000 True NV-P 3 9000 10000 True P . . . . . . . . . . . . . . . n0 2000 False NV

Referring to the table 3, a start LBA and a length of a first partitionPID1 are ‘0’ and ‘5000’, respectively. ‘Writable’ is set to ‘False’, anda write-protection type is ‘P’. A start LBA and a length of a secondpartition PID2 are ‘0’ and ‘4000’, respectively. ‘Writable’ is set to‘True’, and a write-protection type is ‘NV-P’. That is, ‘Writable’ of awrite-protection area LBA0 through LBA4000 of the second partition PID2may be changed by a request of a host 3100, and ‘Writable’ is alwayschanged to ‘False’ after power-off or hardware reset.

A start LBA and a length of a third partition PID3 are ‘9000’ and‘10000’, respectively. ‘Writable’ is set to ‘True and a write-protectiontype is ‘P. A start LBA and a length of an n-th partition PIDn are ‘0’and ‘2000’, respectively. ‘Writable’ is set to ‘False’, and awrite-protection type is ‘NV’. ‘Writable’ of the n-th partition PIDn mayonly be changed by a request of the host 3100.

The following table 4 shows an example where a WP descriptor has been ischanged after power-off or hardware (HW) reset.

TABLE 4 PID (Partition ID) Start LBA Length Writable Type 1 0 5000 TrueP 2 0 4000 False NV-P 3 9000 10000 True P . . . . . . . . . . . . . . .n 0 2000 False NV

Referring to the table 4, ‘Writable’ of the first partition PID1 ischanged from ‘False’ to ‘True’ as compared to table 3. In the table 3,‘Writable’ of a second partition PID2 is set to ‘True’. At power-off orhardware reset, ‘Writable’ of the WP descriptor is changed from ‘True’to ‘False’ because a write-protection type is ‘NV-P’. ‘Writable’ of athird partition PID3 maintains ‘True’. ‘Writable’ may be changed by arequest of the host 3100 because a write-protection type of an n-thpartition PIDn is ‘NV’.

II. Request and Response for Write Protection Setting

In the inventive concepts, it is assumed that a host 3100 and a storagedevice 3200 share a private key in a safe way.

FIG. 7 is a timing diagram showing a request and a response for settingor releasing write protection of a storage system according to anembodiment of the inventive concepts. Referring to FIG. 7, the host 3100provides the storage device 3200 with a request for setting andreleasing write protection. The storage device 3200 receives the requestof the host 3100 and provides a response corresponding to the request.

Referring to FIG. 7, the host 3100 may provide the storage device 3200with four types of requests to set and release write protection. Thatis, the host 3100 provides the storage device 3200 with a WP descriptorupdate counter read request, a WP descriptor read request, a WPdescriptor update request, and a result read request.

The storage device 3200 provides the host 3100 with three types ofresponses in response to a request of the host 3100. That is, thestorage device 3200 provides the host 3100 with a WP descriptor updatecounter read response, a WP descriptor read response, and a result readresponse. The host 3100 may receive responses from the storage device3200 on remaining requests other than the WP descriptor update request.

The following table 5 shows a structure of a data frame for processingeach request and response.

TABLE 5 Name Description Request/Response Four request types for settingand releasing Type write protection and changing its configuration areas follows: (1) 0x1: WP Descriptor Update Counter Read Request (2) 0x2:WP Descriptor Read Request (3) 0x3: WP Descriptor Update Request (4)0x4: Result Read Request Three response types for setting and releasingwrite protection and changing its configuration are as follows: (1) 0x5:WP Descriptor Update Counter Read Response (2) 0x6: WP Descriptor ReadResponse (3) 0x7: Result Read Response WP Descriptor WP descriptorupdate counter requested up to now Update Counter Nonce Random numberfor preventing replay attack WP Descriptor WP descriptor (Request Type =0x3) to be applied WP descriptor (Response Type = 0x6) applied ResultResult on request Success or fail causes HMAC HMAC for checking whetheror not of authenticated request

The host 3100 provides the storage device 3200 with a data frameorganized as illustrated in the table 5 to perform an operationcorresponding to each request. Herein, results of the WP descriptorupdate counter read request and the WP descriptor read request may bechecked through corresponding responses, respectively. In contrast, aresult of the WP descriptor update request may be checked through theresult read request.

Referring to the table 5, ‘WP Descriptor Update Counter’ means a countervalue requested up to now. ‘Nonce’ is a random number for preventingreplay attack. ‘WP Descriptor’ means a WP descriptor to be applied or aWP descriptor applied. ‘Result’ is a result on a request and provideswhether a request succeeds or fails and a fail cause. ‘HMAC’ (Hash-basedMessage Authentication Code) is used to authenticate a request. The host3100 calculates the HMAC for ‘WP Descriptor Update Request’ by means ofa key and a message.

FIG. 8 is a conceptual diagram for describing a method of calculatingHMAC. HMAC (Hash-based Message Authentication Code) may be calculated bya security manager 3234 shown in FIG. 12 of by the HMAC 3250. Referringto FIG. 8, the security manager 3234 calculates the HMAC by means of aprivate key and a message. The message contains ‘Request Type’, ‘WPDescriptor Update Counter’, ‘Nonce’, ‘WP Descriptor’, and ‘Result’. Thesecurity manager 3234 calculates the HMAC by means of MD5, SHA1, SHA256,etc.

Below, requests and responses shown in FIG. 7 will be described.

1. WP Descriptor Update Counter Read Request/Response

A host 3100 requests a WP descriptor update counter, requested up tonow, to set write protection. The host 3100 provides a storage device3200 with a WP descriptor update counter read request to request howmany times a WP descriptor has been updated.

The following table 6 shows a data frame of the WP descriptor updatecounter read request.

TABLE 6 Name Description Request Type 0x1 WP Descriptor Update Counter0x0 Nonce Random number produced by host WP Descriptor 0x0 Result 0x0HMAC 0x0

Referring to the table 6, ‘Request Type’ is ‘0x1’, ‘WP Descriptor UpdateCounter’ is ‘0x0’ (described below), and ‘Nonce’ is a random number thata host generates. The CPU in the host may include a random numbergenerator. ‘WP Descriptor’ is ‘0x0’, ‘Result’ is ‘0x0’, and ‘HMAC’ is‘0x0’.

The storage device 3200 provides the host 3100 with a response shown inthe following table 7 in response to a request shown in the table 6.That is, the host 3100 reads a data frame organized as shown in thefollowing table 7 and checks a current WP descriptor update counter.

TABLE 7 Name Description Response Type 0x5 WP Descriptor Update CounterCurrent value of mobile storage Nonce Random number generated by host WPDescriptor 0x0 Result Execution result of request HMAC HMAC calculatedby mobile storage

Referring to the table 7, ‘Response Type’ is ‘0x5’, ‘WP DescriptorUpdate Counter’ denotes how many the storage device 3200 has updated the‘WP Descriptor’. The security manager 3234 may include a counter that isincremented each time the WP Descriptor is updated. ‘Nonce’ is a randomnumber a host generates and is received in the request. ‘WP Descriptor’is ‘0x0’, ‘Result’ is a result of executing a request, and ‘HMAC’ is avalue calculated by a security manager 3234.

The storage device 3200 calculates ‘HMAC’ by means of values shown inthe following table 8 when generating a data frame shown in the table 7.

TABLE 8 Name Description Private Key Shared private key Response Type0x5 WP Descriptor Update Counter Current value of mobile storage NonceRandom number generated by host WP Descriptor 0x0 Result Executionresult of request

Referring to the table 8, ‘Private Key’ is a key the host 3100 and thestorage device 3200 share (e.g., pre-stored in ROM 3230 duringmanufacture), ‘Response Type’ is ‘0x5’, and ‘WP Descriptor UpdateCounter’ denotes how many the storage device times 3200 updates ‘WPDescriptor’ up to now. ‘Nonce’ is a random number a host generates, ‘WPDescriptor’ is ‘0x0’, and ‘Result’ is a result of executing a request.The host 3100 reads a data frame and then calculates the HMAC. The host3100 authenticates a response by means of the HMAC and checks a ‘Nonce’value to prevent replay attack.

2. WP Descriptor Read Request

To set the write protection, the host 3100 reads a WP descriptorcurrently applied and then checks current setting and configuration. Thehost 3100 provides ‘WP Descriptor Read Request’ to the storage device3200. The following table 9 shows a data frame for ‘WP Descriptor ReadRequest’,

TABLE 9 Name Description Request Type 0x2 WP Descriptor Update Counter0x0 Nonce Random number generated by host WP Descriptor 0x0 Result 0x0HMAC 0x0

Referring to the table 9, ‘Request Type’ is ‘0x2’, ‘WP Descriptor UpdateCounter’ is ‘0x0’, and ‘Nonce’ is a random number a host generates. ‘WPDescriptor’ is ‘0x0’, ‘Result’ is ‘0x0’, and ‘HMAC’ is ‘0x0’.

The storage device 3200 provides the host 3100 with a response shown inthe following table 10 in response to a request shown in the table 9.The host 3100 reads a data frame shown in the table 10 and checks ‘WPDescriptor’.

TABLE 10 Name Description Response Type 0x6 WP Descriptor Update Counter0x0 Nonce Random number generated by host WP Descriptor Current value ofmobile storage Result Execution result of request HMAC HMAC calculatedby mobile storage in table 11

Referring to the table 11, ‘Response Type’ is ‘0x6’, and ‘WP DescriptorUpdate Counter’ is ‘0x0’. ‘Nonce’ is a random number a host generates,‘WP Descriptor’ is a current ‘WP Descriptor’ value of the storage device3200, and ‘Result’ is a result of executing a request. ‘HMAC’ is a valuea security manager 3234 or HMAC 3250 calculates.

The storage device 3200 calculates ‘HMAC’ by means of values shown inthe following table 11 when generating a data frame shown in the table10.

TABLE 11 Name Description Private Key Shared private key Request Type0x6 WP Descriptor Update Counter 0x0 Nonce Random number generated byhost WP Descriptor Current value of mobile storage Result Executionresult of request

Referring to the table 11, ‘Private Key’ is a key the host 3100 and thestorage device 3200 share, ‘Response Type’ is ‘0x6’, and ‘WP DescriptorUpdate Counter’ is ‘0x0’. ‘Nonce’ is a random number a host generates,‘WP Descriptor’ is a current ‘WP Descriptor’ value of the storage device3200, and ‘Result’ is a result of executing a request. A securitymanager 3234 or HMAC 3250 reads a data frame shown in the table 11 andthen calculates the HMAC.

3. WP Descriptor Update Request

To newly set the write protection, the host 3100 newly configures ‘WPDescriptor’ to be applied and requests an update at the storage device3200 by means of the WP descriptor thus configured. To request an updateof ‘WP Descriptor’, the host 3100 generates the HMAC by means of inputvalues shown in the following table 12.

TABLE 12 Name Description Private Key Shared private key Request Type0x3 WP Descriptor Update Counter Current value of mobile storage Nonce0x0 WP Descriptor Descriptor to be changed Result 0x0

Referring to the table 12, ‘Private Key’ is a key the host 3100 and thestorage device 3200 share, ‘Response Type’ is ‘0x3’, and ‘WP DescriptorUpdate Counter’ indicates how many the storage device 3200 updates ‘WPDescriptor’ up to now. ‘Nonce’ is a random number a host generates, ‘WPDescriptor’ is a ‘WP Descriptor’ value to be changed, and ‘Result’ is‘0x0’.

The following table 13 shows a data frame for ‘WP Descriptor UpdateRequest’. The host 3100 provides the storage device 3200 with a dataframe organized as illustrated in the table 13.

TABLE 13 Name Description Request Type 0x3 WP Descriptor Update CounterCurrent value of mobile storage Nonce 0x0 WP Descriptor Descriptor to bechanged Result 0x0 HMAC HMAC calculated by host in table 12

Referring to the table 13, ‘Response Type’ is ‘0x3’, and ‘WP DescriptorUpdate Counter’ indicates how many the storage device 3200 updates ‘WPDescriptor’ up to now. ‘Nonce’ is ‘0x0’, ‘WP Descriptor’ is a value of‘WP Descriptor’ to be changed, and ‘Result’ is ‘0x0’. ‘HMAC’ is a valuethe host 3100 calculates by means of a data frame shown in the table 12.

The host 3100 provides a data frame shown in the table 13 to the storagedevice 3200 to update ‘WP Descriptor’. The storage device 3200 receivesa WP descriptor update request, processes the request normally, andincreases a WP descriptor update counter.

4. Result Read Request/Response

The host 3100 requests an update on ‘WP Descriptor’ and then uses‘Result Read Request’ to check a result on the request. For the resultread request, the host 3100 configures a data frame as illustrated inthe following table 14 and then provides it to the storage device 3200.

TABLE 14 Name Description Request Type 0x4 WP Descriptor Update Counter0x0 Nonce 0x0 WP Descriptor 0x0 Result 0x0 HMAC 0x0

Referring to the table 14, ‘Response Type’ is ‘0x4’, and ‘WP DescriptorUpdate Counter’ is ‘0x0’. ‘Nonce’ is ‘0x0’, ‘WP Descriptor’ is ‘0x0’,and ‘Result’ is ‘0x0’. ‘HMAC’ is ‘0x0’. The storage device 3200 providesthe host 3100 with a response shown in the following table 15 inresponse to a request shown in the table 14. The host 3100 reads a dataframe shown in the table 15 and checks a result of updating ‘WPDescriptor’.

TABLE 15 Name Description Response Type 0x7 WP Descriptor Update CounterCurrent value of mobile storage Nonce 0x0 WP Descriptor 0x0 ResultExecution result of request HMAC HMAC calculated by mobile storage

Referring to the table 15, ‘Response Type’ is ‘0x7’, and ‘WP DescriptorUpdate Counter’ indicates how many the storage device 3200 updates ‘WPDescriptor’ up to now. ‘Nonce’ is ‘0x0’, ‘WP Descriptor’ is ‘0x0’, and‘Result’ is a result of executing a request. ‘HMAC’ is a value thesecurity manager 3234 calculates. The security manager 3234 or HMAC 3250calculates ‘HMAC’ by means of values shown in the following table 16when generating a data frame shown in the table 15.

TABLE 16 Name Description Private Key Shared private key Response Type0x7 WP Descriptor Update Counter Current value of mobile storage Nonce0x0 WP Descriptor 0x0 Result Execution result of request

Referring to the table 16, ‘Private Key’ is a key the host 3100 and thestorage device 3200 share, ‘Response Type’ is ‘0x7’, and ‘WP DescriptorUpdate Counter’ indicates how many the storage device 3200 updates ‘WPDescriptor’ up to now. ‘Nonce’ is ‘0x0’, ‘WP Descriptor’ is ‘0x0’, and‘Result’ is a result of executing a request. The host 3100 reads a dataframe shown in the table 16 and calculates ‘HMAC’.

III. Authentication of WP Descriptor Update Request

FIG. 9 is a flow chart schematically illustrating an HMAC authenticationmethod of a storage system shown in FIG. 3. FIG. 9 shows a method inwhich the storage device 3200 authenticates ‘WP Descriptor UpdateRequest’.

In step S110, a command manager 3232 of a storage device 3200 receives aWP descriptor update request from a host 3100. The storage device 3200updates a write protection's setting in response to the WP descriptorupdate request. That is, the storage device 3200 newly configures a WPdescriptor to be applied.

In step S120, the command manager 3232 parses a data frame of the WPdescriptor update request. The above-described table 13 shows a dataframe of the WP descriptor update request. Referring to the table 13,the data frame contains ‘Request Type’, ‘WP Descriptor Update Counter’,‘WP Descriptor’, ‘Nonce’, ‘Result’, and ‘HMAC’.

In step S130, a security manager 3234 of the storage device 3200calculates the HMAC by means of a shared private key, which has beendescribed with reference to FIG. 8. That is, the security manager 3234calculates the HMAC by means of the private key and a message. Themessage may include ‘Request Type’, ‘WP Descriptor Update Counter’,‘Nonce’, ‘WP Descriptor’, and ‘Result’. The security manager 3234 maycalculate the HMAC by means of MD5, SHA1, SHA256, etc. Alternatively,the HMAC 3250 calculates the HMAC and provides the result to thesecurity manager 3234.

In step S140, the security manager 3234 compares HMAC, obtained from thedata frame of the WP descriptor update request, with the HMAC calculatedin step S130. As shown in the table 13, the data frame provided from ahost 3100 includes ‘HMAC’. The security manager 3234 authenticates theWP descriptor update request by comparing the HMAC from the host 3100with HMAC the storage device 3200 calculates.

In step S150, the security manager 3234 determines whether the WPdescriptor update request is valid, depending on a comparison result ofstep S140. If the HMAC from the host 3100 is equal to the HMACcalculated in the storage device 3200, the security manager 3234determines that the WP descriptor update request is valid. If the HMACfrom the host 3100 is different from the HMAC calculated in the storagedevice 3200, the security manager 3234 determines that the WP descriptorupdate request is invalid.

When the WP descriptor update request is valid, in step S160, thesecurity manager 3234 updates the WP descriptor in response to the WPdescriptor update request. When the WP descriptor update request isinvalid, in step S165, the security manager 3234 rejects the WPdescriptor update request.

IV. Execution of Write-Protection

FIG. 10 is a flow chart for describing a write-protection executionmethod of a storage system shown in FIG. 3. When receiving a writecommand or an erase command from a host 3100, a storage device 3200performs or prevents an operation of writing data at an address area,depending on whether write protection is executed.

In step S210, a command manager 3232 of the storage device 3200 receivesa write command from the host 3100. In step S220, the command manager3232 parses a parameter of the write command. The parameter of the writecommand may contain a start LBA, a length, and a partition ID (PID). Instep S230, a security manager 3234 of the storage device 3200 fetchessdA from a WP descriptor.

In step S240, the security manager 3234 compares a partition ID PID_h ofthe write command with a partition ID PID_d of the WP Descriptor.‘PID_h’ comes from the host 3100, and ‘PID_d’ results from the storagedevice 3200. The security manager 3234 determines whether the partitionID PID_h of the write command is equal to the partition ID PID_d of theWP descriptor.

When the partition ID PID_h of the write command is different from thepartition ID PID_d of the WP descriptor, in step S245, there isdetermined whether the WP descriptor is the last WP descriptor. When theWP descriptor is not the last, the method proceeds to step S230 and thenext WP descriptor is obtained. When the WP descriptor is the last, themethod proceeds to step S295, in which the write command is executed.

Returning to step S250, when the partition ID PID_h of the write commandis equal to the partition ID PID_d of the WP descriptor, the methodproceeds to step S250, in which the security manager 3234 checks‘Writable’ of the WP descriptor. For example, the security manager 3234determines whether ‘Writable’ of the WP descriptor is set to ‘False’.When ‘Writable’ of the WP Descriptor is not set to ‘False’, the methodproceeds to step S245.

When ‘Writable’ of the WP descriptor is set to ‘False’, in step S260,the storage device 3200 checks a length of the WP descriptor. Thestorage device 3200 checks whether the length of the WP descriptor isset to ‘0’. If so, in step S290, the storage device 3200 rejects thewrite command. As described with reference to a table 1, that the lengthof the WP descriptor is set to ‘0’ means that the whole partition iswrite-protected.

When the length of the WP descriptor is not set to ‘0’, in step S270,the security manager 3234 checks a write-protection range indicated bythe start LBA and length of the WP descriptor.

In step S280, the security manager 3234 determines whether the logicalblock address LBA in the write command is in the write-protection range.When the logical block address LBA in the write command is out of thewrite-protection range, the method proceeds to step S245.

When the logical block address LBA of the write command is in thewrite-protection range, in step S290, the storage device 3200 rejectsthe write command. That is, the storage device 3200 write-protects amemory area corresponding to the logical block address LBA and length inthe WP descriptor.

FIG. 11 is a conceptual diagram schematically illustrating an embodimentin which one or more memory areas of a storage system according to anembodiment of the inventive concepts are write-protected. In a storagesystem 3000 shown in FIG. 3, one or more areas of one partition may bewrite-protected. Alternatively, a plurality of areas in a plurality ofpartitions may be write-protected. Referring to FIG. 11, a firstpartition PID1 includes two write-protected areas. A firstwrite-protected area WP1 is from LBA500 to LBA1000, and a secondwrite-protected area WP2 is from LBA2000 to LBA3000. A second partitionPID2 includes one write-protected area. A third write-protected area WP3is from LBA1100 to LBA2200. A third partition PID3 includes threewrite-protected areas. A fourth write-protected area WP4 is from LBA100to LBA600, a fifth write-protected area WP5 from LBA1300 to LBA2000, anda sixth write-protected area WP6 from LBA2900 to LBA3300. The whole ofan n-th partition PIDn is write-protected. An LBA allocation way of theWP descriptor may be changed to set a plurality of write-protected areasat one partition.

A storage system according to an embodiment of the inventive conceptsrelates to a write protection method using ‘Key-ed Crypto Hash’. Forexample, HMAC is a form of ‘Key-ed Crypto Hash. If a command isauthenticated by means of the ‘Key-ed Crypto Hash’, a change in asetting of the write protection may be only made by a host that has aprivate key shared with the storage device, thereby making it possibleto prevent data from being changed by an unauthenticated host. Also, thestorage system according to an embodiment of the inventive conceptsauthenticates a command and simultaneously sets a memory area to bewrite-protected by the logical block address.

In the inventive concepts, the setting of the write protection isaccomplished through authentication that is performed using ‘Key-edCrypto Hash’, ‘Private Key’, ‘Request Count’, and so on, and awrite-protection area is set by a unit of a logical block address of ahost. Also, it is possible to check an unintended change in data bypreventing an unauthenticated host from setting the write protection. Inaddition, the host conducts the write protection dynamically andflexibly by changing a write-protection area by the logical blockaddress.

Meanwhile, the storage system according to an embodiment of theinventive concepts is applicable to a variety of products. The storagesystem according to an embodiment of the inventive concepts may beimplemented in electronic devices, such as a personal computer, adigital camera, a camcorder, a handheld telephone, an MP3 player, aPortable Media Player (PMP), a PlayStation Player (PSP), and a PersonalDigital Assistant (PDA). A storage medium of the storage system may beimplemented with storage devices, such as a memory card, a USB memory,and a Solid State Drive (SSD).

FIG. 14 is a block diagram illustrating a solid state drive to which astorage device according to the inventive concepts is applied. Referringto FIG. 14, a solid state drive (SSD) system 4000 includes a host 4100and an SSD 4200.

The SSD 4200 exchanges signals SGL with the host 4100 through a signalconnector 4211 and is supplied with power through a power connector4221. The SSD 4200 includes a plurality of flash memories 4201 through420 n, an SSD controller 4210, and an auxiliary power supply 4220.

The plurality of flash memories 4201 through 420 n may be used as astorage medium of the SSD 4200. Not only may the SSD 4200 employ theflash memory, but it may employ nonvolatile memory devices, such as(Phase Change Random Access Memory (RAM)) PRAM, (Magnetoresistive RAM)MRAM, (Resistive RAM) ReRAM, and (Ferroelectric RAM) FRAM. The flashmemories 4201 through 420 n are connected with the SSD controller 4210through a plurality of channels CH1 through CHn. One channel isconnected with one or more flash memories. Flash memories connected withone channel may be connected with the same data bus.

The SSD controller 4210 exchanges signals SGL with the host 4100 throughthe signal connector 4211. The signals SGL may include the following: acommand, an address, and data. The SSD controller 4210 is adapted towrite or read out data to or from a corresponding flash memory inresponse to a command of the host 4100. The SSD controller 4210 will bemore fully described with reference to FIG. 15.

The auxiliary power supply 4220 is connected with the host 4100 throughthe power connector 4221. The auxiliary power supply 4220 is charged bya power PWR from the host 4100. The auxiliary power supply 4220 may beplaced inside or outside the SSD 4200. For example, the auxiliary powersupply 4220 may be put on a main board to supply an auxiliary power tothe SSD 4200.

FIG. 15 is a block diagram schematically illustrating an SSD controllershown in FIG. 14. Referring to FIG. 15, an SSD controller 4210 includesa (non-volatile memory) NVM interface 4211, a host interface 4212, anECC circuit 4213, a central processing unit (CPU) 4214, and a buffermemory 4215.

The NVM interface 4211 may scatter data transferred from the buffermemory 4215 into channels CH1 through CHn. The NVM interface 4211transmits data read from flash memories 4201 through 420 n to the buffermemory 4215. The NVM interface 4211 may use a flash memory interfacemanner, for example. That is, the SSD controller 4210 may perform aread, a write, and an erase operation in the flash memory interfacemanner.

The host interface 4212 may provide an interface with an SSD 4200 incompliance with the protocol of the host 4100. The host interface 4212may communicate with the host 4100 by means of USB (Universal SerialBus), SCSI (Small Computer System Interface), PCI express, ATA, PATA(Parallel ATA), SATA (Serial ATA), SAS (Serial Attached SCSI), and soon. The host interface 4212 may also perform disk emulation whichenables the host 4100 to recognize the SSD 4200 as a hard disk drive(HDD).

The ECC circuit 4213 generates an error correction code ECC by means ofdata transferred to the flash memory 4201 through 420 n. The errorcorrection code ECC thus generated is stored at spare areas of the flashmemory 4201 through 420 n. The ECC circuit 4213 detects an error of dataread from the flash memory 4201 through 420 n. If the detected error iscorrectable, the ECC circuit 4213 may correct the detected error.

The CPU 4214 analyzes and processes signals received from a host 4100(refer to FIG. 14). The CPU 4214 controls the host 4100 through the hostinterface 4212 or the flash memories 4201 through 420 n through the NVMinterface 4211. The CPU 4214 controls the flash memories 4201 through420 n by means of firmware for driving an SSD 4200.

The buffer memory 4215 temporarily stores write data provided from thehost 4100 or data read from a flash memory. Also, the buffer memory 4215stores metadata to be stored in the flash memories 4201 through 420 n orcache data. At sudden power-off, the metadata or cache data stored atthe buffer memory 4215 is stored in the flash memories 4201 through 420n. The buffer memory 4215 may be implemented with a DRAM, an SRAM, andso on.

FIG. 16 is a block diagram schematically illustrating an electronicdevice including a storage device according to an embodiment of theinventive concepts. An electronic device 5000 may be implemented with apersonal computer or with handheld electronic devices, such as anotebook computer, a cellular phone, a PDA, and a camera.

Referring to FIG. 16, the electronic device 5000 includes a memorysystem 5100, a power supply 5200, an auxiliary power supply 5250, acentral processing unit (CPU) 5300, a random access memory (RAM) 5400,and a user interface 5500. The memory system 5100 contains a flashmemory 5110 and a memory controller 5120.

FIG. 17 is a block diagram schematically illustrating a memory card towhich a storage device of a user device according to an embodiment ofthe inventive concepts is applied. A memory card system 6000 includes ahost 6100 and a memory card 6200. The host 6100 contains a hostcontroller 6110 and a host connection unit 6120. The memory card 6200includes a card connection unit 6210, a card controller 6220, and aflash memory 6230.

The host 6100 writes data at the memory card 6200 and reads data fromthe memory card 6200. The host controller 6110 provides the memory card6200 with a command (e.g., a write command), a clock signal CLKgenerated from a clock generator (not shown) in the host 6100, and datathrough the host connection unit 6120.

The card controller 6220 stores data at the flash memory 6230 inresponse to a command input through the card connection unit 6210. Thedata is stored in synchronization with a clock signal generated from aclock generator (not shown) in the card controller 6220. The flashmemory 6230 stores data transferred from the host 6100. For example, ifthe host 6100 is a digital camera, the memory card 6200 may store imagedata.

While the inventive concepts has been described with reference toexample embodiments, it will be apparent to those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the inventive concepts. For example, thescope of the inventive concepts may not be limited to a flash memorydevice. The inventive concepts may be applied to all storage devicesthat convert addresses by means of a translation layer. Therefore, itshould be understood that the above embodiments are not limiting, butillustrative.

What is claimed is:
 1. A storage device, comprising: a first memory, thefirst memory being a non-volatile memory; and a second memory configuredto store a write-protect descriptor, the write-protect descriptorincluding a memory partition identifier identifying a partition of thefirst memory, start address information indicating a logical blockaddress for a memory area in the identified memory partition, lengthinformation indicating a length of the memory area in the identifiedmemory partition, writable information in association with the startaddress information and the length information, the writable informationindicating whether to apply write protection to the memory area, and aselection value selected from among at least first to thirdwrite-protection values of a field indicating a kind of write-protectionto apply to the memory area in response to a power-off, a hardwarereset, a power-on, or a request, wherein the field includes the at leastfirst to third write-protection values, the first write-protection valueindicates that the writable information is changed to a first valueafter a powering on of the storage device, the first value indicatingthat the memory area is writable, the second write-protection valueindicates that the writable information is changed to a second valueafter a powering off or a hardware reset of the storage device, thesecond value indicating that the memory area is protected againstwriting, and the third write-protection value indicates that thewritable information is changed by the request.
 2. A method, comprising:receiving, at a storage device, a request, the request including arequest message authentication code, writable information, and writeprotection information, the write protection information including atleast one of start address information, length information, writableinformation indicating whether to apply write protection to a memoryarea, and a selection value selected from among at least first to thirdwrite-protection values of a field indicating a kind of write-protectionto apply to the memory area in response to a power-off, a hardwarereset, a power-on, or the request, the first write-protection valueindicating that the writable information is changed to a first valueafter a powering on of the storage device, the first value indicatingthat the memory area is writable, the second write-protection valueindicating that the writable information is changed to a second valueafter a powering off or a hardware reset of the storage device, thesecond value indicating that the memory area is protected againstwriting, and the third write-protection value indicating that thewritable information is changed by the request, the start addressinformation indicating a logical block address at which the memory areain a non-volatile memory of the storage device starts, and the lengthinformation indicating a length of the memory area; and generating, atthe storage device, a generated message authentication code based on (1)at least one of the start address information and the lengthinformation, and (2) a key stored at the storage device; authenticating,at the storage device, the request based on the generated messageauthentication code and the request message authentication code; andprocessing, at the storage device, the request based on a result of theauthenticating.
 3. The method of claim 2, wherein the write protectioninformation includes both the start address information and the lengthinformation; and the generating generates the generated messageauthentication code based on the start address information, the lengthinformation and the key.
 4. The method of claim 3, wherein the writeprotection information includes the start address information, thelength information and a partition identifier, the partition identifieridentifying a partition in the non-volatile memory of the storagedevice, the partition including the memory area; and the generatinggenerates the generated message authentication code based on the startaddress information, the length information, the partition identifierand the key.
 5. The method of claim 3, wherein the write protectioninformation includes the start address information, the lengthinformation, a partition identifier identifying a partition in thenon-volatile memory of the storage device, the partition including thememory area, and the writable information indicating whether to applywrite protection to the memory area; and the generating generates thegenerated message authentication code based on the start addressinformation, the length information, the partition identifier, thewritable information and the key.
 6. The method of claim 5, wherein thewrite protection information includes the start address information, thelength information, the partition identifier, the writable information,and field indicating a kind of write-protection to apply to the memoryarea; and the generating generates the generated message authenticationcode based on the start address information, the length information, thepartition identifier, the writable information, the field and the key.7. The method of claim 2, wherein the generating generates a hash-basedmessage authentication code.
 8. The method of claim 2, wherein theauthenticating authenticates the request if the generated messageauthentication code matches the request message authentication code; andthe processing processes the request if the request is authenticated. 9.The method of claim 2, wherein the request requests the storage deviceto update the write protection information with information included inthe request.
 10. The method of claim 9, wherein the processingcomprises: incrementing an update counter if the processing processesthe request; and sending a response message if the processing processesthe request, the response message including a count value of the updatecounter.
 11. The method of claim 2, wherein the processing comprises:sending a response message in response to the request if the processingprocesses the request.
 12. The method of claim 2, wherein the processingcomprises: storing, at the storage device, the selection value of thewrite protection information.
 13. The method of claim 12, furthercomprising: receiving, at the storage device, a write command to writedata to the memory area; and determining, at the storage device, whetherto process the write command based on the selection value stored afterreceiving the request.
 14. The method of claim 2, the request is a WPDescriptor Update Request about a write-protect descriptor including thewrite protection information.
 15. The method of claim 14, furthercomprising: receiving a WP Descriptor Read Request from an externaldevice before receiving the request; transmitting a WP Descriptor ReadResponse to the external device in response to the WP Descriptor ReadRequest before receiving the request.
 16. An electronic devicecomprising: a host including a processor configured to execute anapplication program; and a storage device connectable to the electronicdevice and communicating with the host, wherein the storage deviceincludes a first memory being a non-volatile memory and a second memory,the second memory is configured to store a write-protect descriptor, thewrite-protect descriptor including a memory partition identifieridentifying a partition of the first memory, start address informationindicating a logical block address for a memory area in the identifiedmemory partition, length information indicating a length of the memoryarea in the identified memory partition, writable information indicatingwhether to apply write protection to the memory area, and a selectionvalue selected from among at least first to third write-protectionvalues of a field indicating a kind of write protection to apply to thememory area, the field includes the at least first to thirdwrite-protection values, the first write-protection value indicates thatthe writable information is changed to a first value after a power-on ofthe storage device where the first value represents that the memory areais writable, the second write-protection value indicating that thewritable information is changed to a second value after a power-off ofthe storage device or a hardware reset of the storage device where thesecond value represents that the memory area is protected againstwriting, and the third write-protection value indicating that thewritable information is changed by a request of the host.
 17. Theelectronic device of claim 16 wherein the electronic device is one of ahandheld telephone, an MP3 player, a PMP (portable media player), a PDA(personal digital assistant), a camera, a cellular phone, a personalcomputer, a notebook computer, and a handheld electronic device.
 18. Theelectronic device of claim 17, wherein the storage device is a memorycard.
 19. The electronic device of claim 18, wherein the memory card isa UFS (universal flash storage) device.
 20. The electronic device ofclaim 16, wherein the storage device is embedded in the electronicdevice.